This could say a lot about a person. I'll start:

I have 472 discs/sets, here are my top five:

1. Takashi Miike 17
2. Tim Burton 9
3. Russ Meyer 7
4. Sam Raimi 6
4. Peter Jackson 6
4. Kevin Smith 6
4. Kim Ji-Woon 6
4. John Waters 6
4. George Romero 6
5. The Coen Brothers 5
5. Stanley Kubrick 5
5. Robert Rodriguez 5
5. Quentin Tarantino 5
5. Jim Jarmusch 5

Oh, if you count box sets and the individual titles, Alfred Hitchcock is number 2 with 14 titles, and Steven Speilberg jumps in with 6 including the Indiana Jones movies.

Spielberg, Kevin Smith, George Lucas

Off the top of my head:

Hitchcock (all feature-length R1s)
Coen Bros
Kieslowski

Not including double dips:

Hitchcock 34
Ingmar Bergman 17
Martin Scorsese 16
Werner Herzog 13
John Ford 12
Akira Kurosawa 12
Billy Wilder 11
Stanley Kubrick 11
Steven Spielberg 11
Roy William Neill 10
Federico Fellini 10
Francois Truffaut 10
Peter Jackson 9
Fritz Lang 9
Joel Coen 9
Jean Renoir 8
Michael Powell 8
Terry Gilliam 8
Robert Altman 8
Claude Chabrol 8

Mine says I have way too many TV shows on DVD.

James Burrows (24)
Beth McCarthy-Miller (14)
Gail Mancuso (11)
Joss Whedon (11)
Gary Halvorson (10)
Michael Lembeck (10)
Jay Sandrich (10)
James A. Contner (9)
Sheldon Epps (9)

Woody Allen (all of 'em except Bullets Over Broadway)

Hitchcock 15
Miike 10
Romero 9
Coppola 8
Cronenberg 8
Woody Allen 6
Kurosawa 5
Charles Chaplin 5
Tarantino 5
Pete Jackson 4
Jackie Chan 4
John Woo 4
Spielberg 4
Scorcese 4
Craven 4


my counting was very lazy so it's probably not accurate

Steven Spielberg - 12
John Woo - 7
Oliver Stone - 7
Brian De Palma - 6
Tony Scott - 6
Clint Eastwood - 6
Michael Bay - 5
Martin Scorsese - 5
Ridley Scott - 5

Kevin Dunn (20)
John Carpenter (16)
Richard Donner (15)
Clint Eastwood (15)
Steven Spielberg (15)
Wes Craven (14)
Tim Burton (12)
Trey Parker (12)
Dario Argento (11)
Rob Bowman (11)
Gary Halvorson (11)
Walter Hill (11)
Tobe Hooper (11)
Gail Mancuso (11)
Kim Manners (11)

For bettter or for worse. I have pretty everything on DVD by the following directors.....

Stanley Kubrick
Alfred Hitchcock
William Friedkin
Oliver Stone
Darren Aaronofsky
Paul Thomas Anderson
Martin Scorcese
Terry Gilliam
Brad Anderson
Warner Herzog
Michael Mann
Jim Jarmusch
Akira Kurosawa
Spike Lee
Steven Spielberg
Jon Carpenter
Quentin Tarantino
John Boorman
David Cronenberg
Paul Schrader
Tobe Hooper
John Huston
Roman Polanski
Ridley Scott
Peter Jackson

I'm spitballing and I'm sure I've forgotten a bunch. Coppola, Fassbinder,Bergman are a few others that come to mind.

Hitchcock - 29
Bergman - 15
Rohmer - 13
Carpenter - 9

Oddly enough from my modest collection:

Richard Donner - 6
Kevin Smith - 5 (Soon to be 6 when Clerks II comes out)
George Lucas - 5
Chris Columbus - 4
Roland Emmerich - 4
Brett Ratner - 4

Just off the top of my head.

Steven Spielberg
Ridley Scott
Peter Jackson

Don't mean to be 'that guy', but... look here

EDIT: Actually, that was the wrong one, I meant this one" since it wasn't that long ago.

Yeah, this comes up fairly often...

Hitchcock.

I think I have around 45 Hitchcock films. Next up would likely be Spielberg (15).

1. Peter Jackson: 9
2. Akira Kurosawa/George Lucas: 6
3. Quentin Tarantino: 5

Spielberg and Hitchcock.

Alfred Hitchcock - 28
John Ford - 19
Michael Curtiz - 10
Howard Hawks -10
Fritz Lang - 10/12*
Otto Preminger - 10
Henry Hathaway - 9
Elia Kazan - 9
Sam Peckinpah - 9
Roger Corman - 8
Paul Verhoeven - 8
George Cukor - 6
John Sturges - 6
William Wellman - 6

* 10 if you count Dr. Mabuse the Gambler and The Nibelungen as single films, 12 if you count the two parts of each as separte movies.

I don't feel like counting, but I have the most by Hitchcock, Romero, Cronenberg, Lynch, and John Carpenter.

John Carpenter is my #1 with 22 movies.

Clint Eastwood with 21

DVD collection - or are we counting any format (VHS, laserdisc)?

Ridley Scott
Terry Gilliam
Steven Spielberg
Dario Argento

ridley scott, stanley kubrick, john carpenter, martin scorsese

Scorsese with the most
Carpenter
Argento
Lucas
Taratino